IMPORTANT SAFETY INFORMATION

AYVAKIT may cause serious side effects, including:

• Bleeding in your brain. Stop taking AYVAKIT and tell your healthcare provider if you develop any symptoms such as severe headache, vision problems, severe sleepiness, or severe weakness on one side of your body.
• Central nervous system (CNS) effects. CNS side effects are common with AYVAKIT and can be severe. Tell your healthcare provider if you develop any new or worsening CNS symptoms including forgetfulness, confusion, getting lost, trouble thinking, drowsiness, dizziness, trouble sleeping, word finding problems, seeing objects or hearing things that are not there (hallucinations), or change in mood or behavior.

Your healthcare provider may temporarily stop treatment or decrease your dose which may help your symptoms improve. If symptoms do not improve, your healthcare provider may permanently stop treatment with AYVAKIT.

Before taking AYVAKIT, tell your healthcare provider about all of your medical conditions, including if you:

• are pregnant or plan to become pregnant. AYVAKIT can cause harm to your unborn baby.

  • Females who are able to become pregnant:

    • Your healthcare provider should do a pregnancy test before you start AYVAKIT.
    • You should use effective birth control (contraception) during treatment with AYVAKIT and for 6 weeks after the final dose of AYVAKIT. Talk to your healthcare provider about birth control methods that may be right for you.
    • Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with AYVAKIT.
  • Males with female partners who are able to become pregnant should use effective birth control (contraception) during treatment and for 6 weeks after the final dose of AYVAKIT.
• are breastfeeding or plan to breastfeed. It is not known if AYVAKIT passes into your breast milk. Do not breastfeed during treatment with AYVAKIT and for at least 2 weeks after the final dose of AYVAKIT. Talk to your healthcare provider about the best way to feed your baby during this time.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. AYVAKIT may affect the way other medicines work, and certain other medicines may affect how AYVAKIT works. Talk to your healthcare provider prior to starting a new medicine.

What should I avoid while taking AYVAKIT?

Do not drive or operate hazardous machinery, if you have confusion or trouble thinking during treatment with AYVAKIT.

The most common side effects of AYVAKIT include:

• fluid retention or swelling
• nausea
• tiredness
• muscle weakness
• vomiting
• diarrhea
• decreased appetite
• stomach area (abdominal) pain
• increased eye tearing
• constipation
• rash
• dizziness, and
• hair color changes

These are not all of the possible side effects of AYVAKIT. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Please see the full Prescribing Information and Patient Information for AYVAKIT.

WHAT IS AYVAKIT?

AYVAKIT is a prescription medicine used to treat adults with a certain type of stomach, bowel, or esophagus cancer called GIST that cannot be treated with surgery or that has spread to other parts of the body (metastatic), and that is caused by certain abnormal PDGFRA genes. Your healthcare provider will perform a test to make sure that you have this abnormal PDGFRA gene and that AYVAKIT is right for you.

It is not known if AYVAKIT is safe and effective in children.